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CY803/802
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CY803/802 Datasheet
300M-450MHz RF receiver
General Description The CY803/802 is a general purpose, 3.3-5V,
super-heterodyne Receiver that operates from
300M to 450MHz with typical sensitivity of
-110dBm. The CY803/802 functions as a
super-heterodyne receiver for OOK and ASK
modulation up to 10kbps.The down-conversion
mixer also provides image rejection. All
post-detection data filtering is provided on the
CY803/802. Any one-of-four filter bandwidths
may be selected externally by the user in binary
steps, from 1.25kHz to 10kHz. The user need
only configure the device with a set of easily
determined values, based upon data rate, code
modulation format, and desired duty-cycle
operation.
Features
• Image Rejection Mixer
Frequency from 300MHz to 450MHz
• Low power, 6.0mA @ 433.92MHz,
continuous on
• data rates to 10kbps (Manchester
Encoded)
• High sensitivity: -110dBm
• No IF filter required
• Excellent selectivity and noise rejection
• Low external part count
Ordering Information
Typical Application
Part Number Temperature Range Package
CY802 –40° to +85°C 16-Pin SOP
CY803 –40° to +85°C 16-Pin SSOP
CY803/802
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Pin Configuration
Pin Description
CY803/802
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Absolute Maximum Ratings(1)
Supply Voltage(VDD) .................................................+5V
Input Voltage .............................................................+5V
Junction Temperature .........................................+150ºC
Lead Temperature (soldering, 10sec.) .................. 260°C
Storage Temperature (TS) .....................-65ºC to +150°C
Maximum Receiver Input Power ........................+10dBm
ESD Rating(3) .................................................. 2KV CDM
...................................................200V HBM
................................ 100V Machine Model
Operating Ratings(2)
Supply voltage (VDD) ..............................+3.3V to +5.5V
Ambient Temperature (TA) ................. –40°C to +105°C
Input Voltage (VIN) ........................................5.5V (Max)
Maximum Input RF Power ................................ –20dBm
Electrical Characteristics(4)
Specifications apply for 3.0V < VDD < 3.6V, VSS = 0V, CAGC = 4.7μF, CTH = 0.1μF, fRX = 433.92 MHz,
unless otherwise noted. Bold values indicate –40°C – TA – 105°C. 1kbps data rate (Manchester
encoded), reference oscillator frequency = 13.52127MHz.
CY803/802
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Note 1. Exceeding the absolute maximum rating may damage the device.
Note 2. The device is not guaranteed to function outside of its operating rating.
Note 3. Device is ESD sensitive. Use appropriate ESD precautions. Exceeding the absolute
maximum rating may damage the device.
Note 4. Sensitivity is defined as the average signal level measured at the input necessary to
achieve 10-2 BER (bit error rate). The input signal is defined as a return-to-zero (RZ) waveform
with 50% average duty cycle (Manchester encoded) at a data rate of 1kbps.
Note 5. When data burst does not contain preamble, duty cycle is defined as total duty cycle,
including any “quiet” time between data bursts. When data bursts contain preamble sufficient to
charge the slice level on capacitor C , then duty cycle is the effective duty cycle of the burst alone.
[For example, 100msec burst with 50% duty cycle, and 100msec “quiet” time between bursts. If
burst includes preamble, duty cycle is TON /(TON+TOFF )= 50%; without preamble, duty cycle is
TON /( TON+TOFF + Tquiet ) = 50msec/(200msec)=25%. TON is the (Average number of 1’s/burst)
× bit time, and TOFF= T BURST– TON).
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Typical Characteristics Sensitivity Graphs
CY803/802
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Functional Diagram
Figure 1, CY803/802 Simplified Block Diagram.
Functional Description Figure 1. Simplified Block Diagram that
illustrates the basic structure of the CY803/802.
It is made of three sub-blocks; Image Rejection
UHF Down-converter, the OOK Demodulator,
and Reference and Control Logics. Outside the
device, the CY803/802 requires only three
components to operate: two capacitors (CTH,
and CAGC) and the reference frequency device,
usually a quartz crystal. An additional five
co mp o nent s ma y b e used to imp ro ve
performance. These are: power supply
decoupling capacitor, two components for the
matching network, and two components for the
pre-selector band pass filter.
Receiver Operation LNA
The RF input signal is AC-coupled into the gate
circuit of the grounded source LNA input stage.
The LNA is a Cascoded NMOS.
Mixers and Synthesizer
The LO ports of the Mixers are driven by
quadrature local oscillator outputs from the
synthesizer block. The local oscillator signal
from the synthesizer is placed on the low side of
the desired RF signal to allow suppression of the
image frequency at twice the IF frequency below
the wanted signal. The local oscillator is set to
32 times the crystal reference frequency via a
phase-locked loop synthesizer with a fully
integrated loop filter.
Image Reject Filter and Band-Pass Filter
The IF ports of the mixer produce quadrature
down converted IF signals. These IF signals are
low-pass filtered to remove higher frequency
products prior to the image reject filter where
they are combined to reject the image
frequencies. The IF signal then passes through a
third order band pass filter. The IF center
frequency is 1.2MHz. The IF BW is 330kHz @
433.92MHz, and this varies with RF operating
frequency. The IF BW can be calculated via
direct scaling:
CY803/802
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These filters are fully integrated inside the
CY803/802. After filtering, four active gain
controlled amplifier stages enhance the IF signal
to proper level for demodulation.
OOK Demodulator
The demodulator section is comprised of detector,
programmable low pass filter, slicer, and
AGC comparator.
Detector and Programmable Low-Pass Filter
The demodulation starts with the detector
removing the carrier from the IF signal. Post
detection, the signal becomes base band
information. The programmable low-pass filter
further enhances the base band information.
There are four programmable low-pass filter BW
settings: 1625Hz, 3250Hz, 6500Hz, 13000Hz for
433.92MHz operation. Low pass filter BW will
vary with RF Operating Frequency. Filter BW
values can be easily calculated by direct scaling.
See equation below for filter BW calculation:
It is very important to choose the filter setting
that best fits the intended data rate to minimize
data distortion. Demod BW is set at 13000Hz @
433.92MHz as default (assuming both SEL0 and
SEL1 pins are floating). The low pass filter can
be hardware set by external pins SEL0 and
SEL1.
Table 1. Demodulation BW Selection
Slicer, Slicing Level and Squelch
The signal prior to slicer is still linear
demodulated AM. Data slicer converts this
signal into digital “1”s and “0”s by comparing
with the threshold voltage built up on the CTH
capacitor. This threshold is determined by
detecting the positive and negative peaks of the
data signal and storing the mean value. Slicing
threshold default is 50%. After the slicer the
signal is now digital OOK data.
During long periods of “0”s or no data period,
threshold voltage on the CTH capacitor may be
very low. Large random noise spikes during this
time may cause erroneous “1”s at DO pin.
Squelch pin when pull down low will suppress
these errors.
AGC Comparator
The AGC comparator monitors the signal
amplitude from the output of the programmable
low-pass filter. When the output signal is less than
750mV thresh-hold, 1.5μA current is sourced into
the external CAGC capacitor. When the output
signal is greater than 750mV, a 15μA current sink
discharges the CAGC capacitor. The voltage
developed on the CAGC capacitor acts to adjust
the gain of the mixer and the IF amplifier to
compensate for RF input signal level variation.
Reference Control
There are 2 components in Reference and Control
sub-block: 1) Reference Oscillator and 2) Control
Logic through parallel Inputs: SEL0, SEL1, SHDN
Reference Oscillator
Figure 2: Reference Oscillator Circuit
The reference oscillator in the CY803/802 (Figure
2) uses a basic Colpitts crystal oscillator
configuration with MOS transconductor to provide
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negative resistance. All capacitors shown in Figure
2 are integrated inside CY803/802. R01 and R02
are external pins of CY803/802. User only needs to
connect reference oscillation crystal.
Reference oscillator crystal frequency can be
calculated:
FREF OSC = FRF/(32 + 1.1/12)
For 433.92 MHz, FREF OSC = 13.52127 MHz.
To operate the CY803/802 with minimum offset,
crystal frequencies should be specified with 10pF
loading capacitance.
Application Information
Figure 3. CY803/802 Application Example, 433.92 MHz
The CY803/802 can be fully tested by using one of
many evaluation boards designed at CY for this
device. As an entry level, the CY803/802 (Figure 3)
offers a good start for most applications. It has a
helical PCB antenna with its matching network, a
band-pass-filter front-end as a pre-selector filter,
matching network and the minimum components
required to make the device work, which are a
crystal, Cagc, and Cth capacitors. By removing the
matching network of the helical PCB antenna (C9
and L3), a whip antenna (ANT2) or a RF
connector (J2) can be used instead. Figure 3 shows
the entire schematic of it for 433.92MHz. Other
frequencies can be used and the values needed are
in the tables below. Capacitor C9 and inductor L3
are the passive elements for the helical PCB
matching ne twork. A t ight to le rance i s
recommended for these devices, like 2% for the
inductor and 0.1pF for the capacitor. PCB
variations may require different values and
optimization. Table 2 shows the matching elements
for the device frequency range. For additional
information look for Small PCB Antennas for CY
RF Products application note.
Table 2. Matching Values for the Helical PCB Antenna
To use another antenna, like the whip kind, remove
C9 and place the whip antenna in the hole provided
in the PCB. Also, a RF signal can be injected there.
L1 and C8 form the pass-band-filter front-end. Its
purpose is to attenuate undesired outside band noise
which reduces the receiver performance. It is
calculated by the parallel resonance equation f =
1/(2×PI×(SQRT L1×C8)). Table 3 shows the most
used frequency values.
Table 3. Band-Pass-Filter Front-End Values
There is no need for the band-pass-filter front-end
for applications where it is proven that the outside
band noise does not cause a problem. The
CY803/802 has image reject mixers which improve
significantly the selectivity and rejection of outside
band noise.
CY803/802
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Capacitor C3 and inductor L2 form the L-shape
matching network. The capacitor provides
additional attenuation for low frequency outside
band noise and the inductor provides additional
ESD protection for the antenna pin. Two methods
can be used to find these values, which are
matched close to 50Ω. One method is done by
calculating the values using the equations below
and another by using a Smith chart. The latter is
made easier by using software that plots the values
of the components C8 and L1, like WinSmith by
Noble Publishing.
To calculate the matching values, one needs to
know the input impedance of the device. Table 4
shows the input impedance of the CY803/802 and
suggested matching values for the most used
frequencies. These suggested values may be
different if the layout is not exactly the same as the
one made here.
Table 4: matching values for the most used
frequencies For the frequency of 433.92MHz, the
input impedance is Z = 18.6 – j174.2Ω, then the
matching components are calculated by,
Equivalent parallel = B = 1/Z = 0.606 + j5.68
msiemens
Rp = 1 / Re (B); Xp = 1 / Im (B)
Rp = 1.65kΩ; Xp = 176.2Ω
Q = SQRT (Rp/50 + 1)
Q = 5.831
Xm = Rp / Q
Xm = 282.98Ω
Resonance Method For L-shape Matching
Network
Lc = Xp / (2×Pi×f); Lp = Xm / (2×Pi×f)
L2 = (Lc×Lp) / (Lc + Lp); C3 = 1 /
(2×Pi×f×Xm)
L2 = 39.8nH
C3 = 1.3pF
Figure 4: device’s input impedance, Z = 18.6 – j174.2Ω
Doing the same calculation example with the
Smith Chart, it would appear as follows,
Figure 4: device’s input impedance, Z = 18.6 – j174.2Ω
First, we plot the input impedance of the device,
(Z = 18.6 – j174.2)Ω @ 433.92MHz (Figure 4).
Second, we plot the shunt inductor (39nH) and
the series capacitor (1.5pF) for the desired input
impedance (Figure 5). We can see the matching
leading to the center of the Smith Chart or close
to 50Ω.
CY803/802
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Figure 5. Plotting the Shunt Inductor and Series
Capacitor
Crystal Y1 or Y1A (SMT or leaded respectively)
is the reference clock for all the device internal
circuits. Crystal characteristics of 10pF load
capacitance, 20ppm, ESR < 50Ω, -40ºC to
+85ºC temperature range are desired. Table 5
shows the crystal frequencies and one of CY
company approved crystal manufacturers.
The oscillator of the CY803/802 is a Colpitts
type. It is very sensitive to stray capacitance
loads. Thus, very good care must be taken when
laying out the printed circuit board. Avoid long
traces and ground plane on the top layer close to
the REFOSC pins RO1 and RO2. When care is
not taken in the layout, and crystals from other
vendors are used, the oscillator may take longer
times to start as well as the time to good data in
the DO pin to show up. In some cases, if the
stray capacitance is too high (> 20pF), the
oscillator may not start at all.
The crystal frequency is calculated by REFOSC
= RFCarrier/(32+(1.1/12)). The local oscillator
is low side injection (32 × 13.52127MHz =
432.68MHz), that is, its frequency is below the
RF carrier frequency and the image frequency is
below the LO frequency. See Figure 6. The
product of the incoming RF signal and local
oscillator signal will yield the IF frequency,
w h i c h w i l l b e d e m o d u l a t e d b y t h e
detector of the device.
Figure 6. Low Side Injection Local Oscillator.
REFOSC (MHz) Carrier (MHz) CY Part Number
12.15269 390.0 JMR-12.15269M
13.02519 418.0 JMR-13.02519M
13.52127 433.92 JMR-13.52127M
Table 5. Crystal Frequency and Vendor Part Number.
JP1 and JP2 are the bandwidth selection for the
demodulator bandwidth. To set it correctly, it is
necessary to know the shortest pulse width of the
encoded data sent in the transmitter. Like in the
example of the data profile in the figure 7 below,
PW2 is shorter than PW1, so PW2 should be
used for the demodulator bandwidth calculation
which is found by 0.65/shortest pulse width.
After this value is found, the setting should be
done according to Table 6. For example, if the
pulse period is 100μsec, 50% duty cycle, the
pulse width will be 50μsec (PW = (100μsec ×
50%) / 100). So, a bandwidth of 13kHz would be
CY803/802
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necessary (0.65 / 50μsec). However, if this data
stream had a pulse period with 20% duty cycle,
the bandwidth required would be 32.5kHz (0.65
/ 20μsec), which exceeds the maximum
bandwidth of the demodulator circuit. If one
tries to exceed the maximum bandwidth, the
pulse would appear stretched or wider. Other
frequencies will have different demodulator
bandwidth limits, which are derived from the
reference oscillator frequency. Table 7 and Table
8 below shows the limits for the other two most
used frequencies.
Table 6. JP1 and JP2 setting, 433.92 MHz.
Table 7. JP1 and JP2 setting, 418.0 MHz.
Table 8. JP1 and JP2 setting, 390.0 MHz.
Capaci to rs C6 and C4, C T H and C A G C
respectively provide time base reference for the
data pattern received. These capacitors are
selected according to data profile, pulse duty
cycle, dead time between two received data
packets, and if the data pattern has or does not
have a preamble. See Figure 7, example of a data
profile.
Figure 7. Example of a Data Profile.
For best results the capacitors should always be
optimized for the data pattern used. As the baud
rate increases, the capacitor values decrease.
Table 9 shows suggested values for Manchester
Encoded data, 50% duty cycle.
Table 9. Suggested CTH and CAGC Values.
JP3 is a jumper used to configure the digital
squelch function. When it is high, there is no
squelch applied to the digital circuits and the DO
(data out) pin has a hash signal. When the pin is
low, the DO pin activity is considerably reduced.
It will have more or less than shown in the figure
below depending on the outside band noise. The
penalty for using squelch is a delay in getting a
good signal in the DO pin, that is, it takes longer
for the data to show up. The delay is dependent
upon many factors such as RF signal intensity,
data profile, data rate, CTH and CAGC capacitor
values, and outside band noise. See Figure 8 and
Figure 9 below.
Figure 8. Data Out Pin with No Squelch (SQ = 1).
CY803/802
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Figure 9. Data Out Pin with Squelch (SQ = 0).
Other components used are C5, which is a
decoupling capacitor for the Vdd line, R4
reserved for future use and not needed for the
evaluation board, R3 for the shutdown pin
(SHDN = 0, device is operation), which can be
removed if that pin is connected to a
microcontroller or an external switch, R1 and R2
which form a voltage divider for the AGC pin.
One can force a voltage in this AGC pin to
purposely decrease the device sensitivity.
Special care is needed when doing this operation,
as an external control of the AGC voltage may
vary from lot to lot and may not work the same
for several devices.
Three other pins are worthy of comment. They
are the DO, RSSI, and shut down pin. The DO
pin has a driving capability of 0.4mA. This is
good enough for most of the logic family ICs in
the market today. The RSSI pin provides a
transfer function of the RF signal intensity vs
voltage. It is very useful to determine the signal
to noise ratio of the RF link, crude range
estimate from the transmitter source and AM
demodulation, which requires a low CAGC
capacitor value.
The shut down pin (SHDN) is useful to save
energy. When its level close to VDD (SHDN = 1),
the device is not in operation. Its DC current
consumption is less than 1μA (do not forget to
remove R3). When toggling from high to low,
there will be a time required for the device to
come to steady state mode, and a time for data to
show up in the DO pin. This time will be
depe ndent up o n man y things such a s
temperature, crystal used, and if the there is an
external oscillator with faster startup time.
Normally, with the crystal vendors suggested,
the data will show up in the DO pin around
1msec time, and 2msec over the temperature
range of the device. When using an external
oscillator or reference oscillator signal, the time
is reduced considerably and can be around
140μsec. See Figures Figure 10 and 11.
Figure 10: Time-to-Good Data After Shut Down Cycle,
Room Temperature.
Figure 11. Time to Good Data, External Oscillator, Room
Temperature.
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Figure1 CY803/802 Receiver 433.92MHz Module
CY803/802 Bill of Materials, 433.92 MHz
Item Manufacturer Description Qty.
C1 MuRata 5.6pF , 0402/0603 1
C2 MuRata 1.5pF , 0402/0603 1
C3 MuRata 0.1uF , 0402/0603 1
C4 MuRata 1uF , 0402/0603 1
C6 MuRata 0.47uF , 0402/0603 1
C7 MuRata 1uF, 0402/0603 1
JP1 short 1
JP2 short 1
R3 75Kohm 1
CY803/802
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Figure1 CY803/802 Receiver 315MHz Module
CY803/802 Bill of Materials, 315 MHz
L1 MuRata 22nH 5%, 0402/0603 1
L2 MuRata 39nH 5%, 0402/0603 1
U1 CY803/802 SSOP-16/SOP-16 1
Y1 CY13.52127MHz HC49S 1
Item Manufacturer Description Qty.
C1 MuRata 6.8pF , 0402/0603 1
C2 MuRata 1.8pF , 0402/0603 1
C3 MuRata 0.1uF , 0402/0603 1
C4 MuRata 1uF , 0402/0603 1
C6 MuRata 0.47uF , 0402/0603 1
C7 MuRata 1uF, 0402/0603 1
JP1 short 1
JP2 short 1
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CY803/802 Module Mechanical Size: (unit: mm)
SSOP16 Module Shape
R3 75Kohm 1
L1 MuRata 39nH 5%, 0402/0603 1
L2 MuRata 68nH 5%, 0402/0603 1
U1 CY803/802 SSOP-16/SOP-16 1
Y1 CY9.81563MHz HC49S 1
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SOP16 Module Shape
Package Information: (unit: mm)
SSOP16 Package
CY803/802
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SOP16 Package
CY803/802
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CY803/802 PCB antenna:
CY803/802
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For more information and assistance, please contact us as follows:
CY WIRELESS TECHNOLOGY LIMITED
Add: Rm.1407, Block C, Tairan Building, 8th Tairan Road, Futian District,
Shenzhen, Guangdong Province, China
Website:www.rficy.com
Email: [email protected]